Thermostatic hot-water heating system for automobiles



March 23, 1954 s. VERNE-r ET Al.

THERMOSTATIC HOT-WATER HEATING SYSTEM FOR AUTOMOBILES 2 Shets-Sheet l Filed April 19, 195o IN V EN TORS. s VEA-'NET 4L/mv C. HorFMn/v,

ATTQRN EYS.

Filed April 19, 1950 March 23, 1954 s, VERNE-r ET AL 2,673,038

THERMOSTATIC HOT-WATER HEATING SYSTEM FOR AUTOMOBILES 2 Sheets-Sheet 2 INVENTORS. SERG/us MER/var "a4/.AN C'. Ha-PMAM,

BY Y

ATTOQNEYS.

Patented Mar. 23, 1954 THERMOSTATIC HOT-WATER HEATING:l SYSTEM FOR AUTOMOBILES Sergius Vernet andl Allan C. Hoffman, Yellow Springs, Ohio, assignors toVernay Laboratories` Inc., Yellow Springs, Ohio, a corporation of Ohio Application April 19, 1950, Serial No. 156,780

` (c1. zar- 8) 3v Claims.

This invention relates to a thermostat and a thermostat system and more particularly to a thermostat and system useful in connection with the control of hot water heating systems for automobiles. As pointed out in the copending application of Allan C. Hoffman, Serial No. 87,220, led April 13, 1949, now Patent No. 2,634,057, a study of the relationship between outside air temperature, ram air temperature, Water temperature in and out of the heater, air temperature in and out of the heater and car temperatures in connection with speeds of travel have shown that changes in water oW and air now and water and air temperatures were of considerable magnitude during normal driving operations. It was found that while both air flow and water flow increase as the car speed increases the proportionate relationship from the heat balance standpoint does not hold throughout the normal driving speed of an automobile.

Further, according to the disclosure of the said copending application, best results have been obtained when the temperature of the passenger compartment is controlled by controlling the flow of water through the heater. done by actuating the water valve in response to changes in thetemperature of Water coming from the heater.

There are however other temperatures which, as pointed out above, are important in controlling the temperature of the passenger compartment. In the rst place, the temperature of the ambient air in the compartment to which the passengers are subjected must be considered. Secondly, it is important to consider the temperature of the hot air issuing from the heater. It is important also to determine the temperature ofthe outside air entering the heater, and it is also important in many cases to determine the temperature of the water returning from` the heater core to the engine radiator.

With the foregoing considerations in mind, it

eration of the valve isa` function of changes in various sensings.

Preferably this is According to our preferred Ancillary tothe foregoing object is the'object of providing a thermostat system of a particular nature having a sensing element or elements' whichv can be disposed in a plurality of diierent locations to obtain a combined or integrated sensing,

Yet another object of our invention is the provision of a device as outlined above in which manual control means are provided so that the full closed or full open positions of the valve can be changed manually when conditions require such a change.

One of the basic objects of our invention lies in the provision of an arrangement whereby the sensing element is utilized to transmit motion from the manual control to the valve.

These and other objects of our invention which will become clear to those skilled in the art uponl reading these specications, or which we` shallexplain in more detail hereinafter, we accomplish by that certain construction and arrangement of parts of which we shall now` describe several exemplary' embodiments.

Reference is made tothe drawings forming a part hereof and in` which:

Figure l is a general fragmentary cross section.. al View of a device according to our invention.

Figure 2 is an enlarged cross sectional View taken on the line 2--2 of Figure 1.

Figure 3 is a diagram showing one way inwhich the device of Figure 1 may be incorporated with an automobile heating system.

Figure 4 is a View similar to Figure 3 showing another embodiment thereof, and

Figure 5 is a. view similar to Figures 2V and 4 showing still another embodiment thereof.

` Briey, inthe practice of our invention we provide a sealed system charged with a liquid which changes involume in response to` changes in ternperature and which will maintain a fairly con.- stant viscosity over a temperature range from about 40 F. to about` +212 F. The sealed system is provided with a cylinder having a piston therein` which piston is thus actuated in response to volume changes of the liquid in the system` and which piston is operatively connected to a valve in the water circuit. A manual` control is.

provided by the addition of another cylinder and piston in which the piston is manually settable` to change` the operating range of the: rst piston. The system includes a substantial length of capillary tubing which tubing may be` disposed in various locations to obtain an integrated sensing for the actuation of the valve. ThusV it is; possible,V with the' above described device to obtain sensings to control the valve from the ambient temperature in the passenger compartment, the temperature of the air issuing from the heater, the temperature of the air entering the heater, the temperature of the water returning from the heater core to the engine radiator or from any one or a combination of Vthese locations.

Referring now more particularly to the drawings, we have shown in Figure 1 a valve body indicated generally at IIIl through which water in the water circuit between the heater core and the car engine ilows through fittings II and I2. The valve member itself is indicated at I3 and comprises a disc having an annular groove in which is seated a rubber ring I4. The valve stem is indicated at I5 and has an extension I 6 to which is secured a guide flange I1 having perforations I5 for the passage of water. The guide iiange I'I rides in the fitting II to maintain the stem I5 in alignment.

As best seen in Figure 2', the valve stem I5 terminates in the piston I9 operating in the cylinder 29. r)The stem I5 is provided with the annular groove 2l in which is mounted a split ring 32 against which the cup 23 bears by means of its central `flange 24. Its peripheral flange 25 serves as a seat for the compression spring 25, the other end of which bears against a shoulder l in the valve body I0. The spring 25 bearing against the ange 25 of the cup 23 insures the valve being moved toward the right to open position when no pressure is on the piston I 9.`

The valve body is ilanged as indicated at 28 and a cylinder mounting plate 29 is secured to the flange 28 as by means of the fastening 3B.

Secured to the cylinder 20 is a chamber 3l having an internal annular shoulder 32 in opposition to the flange 33 on the cylinder body. A diaphragm 34 is clamped between the shoulder 32 and flange 33 by an inturned flange 35 forming a portion of the chamber 3I. Preferably the chamber 3l is secured and sealed to the mounting plate 29 by a washer 3'I held in place by a snap ring 38 seating in a suitable groove in the cylinder 2t, and a compression gasket 36.

The chamber 3| is substantially duplicated as seen in Figure 1 by a chamber 39 similarly secured to a cylinder 4I) in clamping relation with a diaphragm 4l, and the cylinder 40 contains -a piston 42. In the structure of Figure 1 the cylinder 45 is externally threaded, and a nut 43 is in engagement therewith and bears against a Washer 43a. A compression spring 43h is held between the washer 43a and a shell member 44. The shell member 44 has a closing member 45a provided with a threaded boss 44h, through which is threaded the shank 45h of the piston. Adjustment is accomplished by means of the knob 45, acting through the shank 45h, piston 42 and diaphragm 4 I rIhe chambers 3| and 39 are connected by a substantial length of capillary tubing indicated at 45. Preferably one of the chambers, 3l or 39, is provided with an addition-al length of capillary tubing 4l' which in its initial condition may serve as a charging tube and which is then sealed at its ends. It will be understood that in some installations the tubeV 41 may be left as short as will permit of its usel as a charging tube while in other installations the tube 4'! may itself have substantial length and be used as a sensing element in various locations, as will be more fully pointed out hereinafter.

From the foregoing description it will be understood that the chambers 3|, 39and the tubing 46 and 41 all taken together constitute a closed and sealed system. This system is charged preferably through the tube 41 with a liquid which has the characteristic of expanding in volume with an increase in temperature land which has a fairly constant viscosity over a wide range of temperatures as pointed out above. It will now be clear that with any given setting of the manual control knob 45, any expansion of the liquid in the sealed system will cause the piston I5 to move toward the left to a position to reduce the valve opening or ultimately to shut the valve off entirely. Since, after the valve has shut, sensings may still tend to push the piston I5 toward the left, means are provided to permit an override. Thus, after the valve disc I3 has contacted the limiting shoulder portion Illa, the spring 43h will yield, permitting movement of the members 39, 40, 43 and 43a toward the left so that no strain is placed upon the structure.

If there is a drop in temperature to which the tubing 46 or 41 is subjected, the liquid within the system will contract and pressure will be removed from the piston I 5 whereupon the spring 26 will return the valve I3 toward open position.

It will be understood that with any given set of temperature sensings and with the valve in any given position resulting therefrom the position of the valve can be adjusted at will by means of the control knob 45. If the control knob 45 is turned to screw the member 45h into the boss 44h, the piston 42 will be moved toward the left and the piston I5 will be forced to move a corresponding distance toward the left. Similarly, if the member 45a is unscrewed slightly from the boss 44D, the piston I5 will follow the movement of the piston 42.

.The diaphragms 34 and 4I are rubber, either natural or synthetic, and serve to seal the liquid system. The pressure of the liquid is transmitted through the diaphragms respectively to the pistons I5 and 42.

The liquid which is used in the system may be any liquid which exhibits the characteristics pointed out above. As an example of a highly satisfactory liquid, although it is somewhat expensive, we may cite Silicone. As another example of a liquid which is much less expensive,

`we may cite any ordinary S. A. E. 10W engine lubricating oil.

In charging the system through the charging tube 41 it will be found `desirable to charge the system to a pressure of about 500 pounds per square inch. In actual operation the operating pressures within the system may attain a value of 2000 or 3000 pounds per square inch. For these reasons the chambers and capillary tubings must be of such strength that they can withstand the operating pressures likely to be encountered.

In Figures 3, 4 and 5 we have shown various ways in which our invention may be applied to an automotive heating system. Thus, in Figure 3 the valve Iis again indicated generally at Il), and in this instance it is placed in the line between the engine indicated at E and the heater core indicated at H. In this particular embodiment the dashboard is indicated at D and the manual control 45 is located on the dash.-

, board. Thus the capillary tubing 46 is positioned 1 the passenger compartment indicated at AO and.

then it is led into the duct through which the water is returned from the heater core H to the engine E. This duct is indicated at WO. In Figure 3 air enters the heater through the duct indicated at AI and is fed to the heater core H by the fan F.

In Figure 4 corresponding parts have been given the same reference numerals. Here the tube 41 has not been extended as in Figure 4, but the tube 46 in this instance is positioned in part Within the duct AO to which the air issuing from the heater passes. Thus, the element 4B can sense not only the temperature of the ambient air in the passenger compartment but the temperature of the hot air issuing from the heater.

In Figure 5 again the various parts have been given corresponding reference numerals. Here the element -46 is positioned as in Figure 4, but the tube 41 has been extended and has been placed in the air path in the duct AI so as to sense the temperature of the outside air entering the heater.

It will be clear that numerous modiiications may be made in the disposition of the elements and that more tubes 41 could be provided to sense yet other temperatures if found to be advisable. It will therefore be clear that We do not intend to limit ourselves to the specic embodiments shown but that we are to be limited by the claims which follow.

Having now fully described our invention, what We claim as new and desire to secure by Letters Patent is:

l. In an automobile having a hot water heating system wherein engine radiator water is circuited through a heater core, and wherein outside air is blown past said heater core and into the passenger compartment of said car there being a valve in said Water circuit, a thermostat system comprising a chamber associated with the dashboard of said automobile and a chamber associated with said valve, each of said chambers including a cylinder and a piston therein, the piston of the chamber associated with the dashboard being manually settable in relation to its cylinder, and the piston of the chamber associated with the valve being operatively connected to said valve, each of said chambers constituting a thermostat, said thermostat associated with said valve sensing hot water temperature, and said thermostat associated with said dashboard sensing car temperature, capillary tubing connected to said chambers, said chambers and tubing being charged with a liquid which changes in volume in response to changes in temperature, said capillary tubing being of substantial length, and a portion of said tubing being disposed to sense the temperature of water flowing through said heater.

2. A thermostat system according to claim 1, wherein a portion of said tubing is disposed to sense the temperature of Water leaving said heater core.

3. A thermostat system according to claim 1, wherein the tubing connected to said chamber comprises a length oi tubing connecting said chambers together, and an additional length of tubing connected to one of said chambers at one end and sealed at its other end, said additional length of tubing being disposed to sense the temperature of Water leaving said heater core.

SERGIUS VERNET. ALLAN C. HOFFMAN.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 1,971,532 McAuley Aug. 28, 1934 2,164,882 Miles July 4, 1939 2,208,149 Vernet July 16, 1940 2,214,236 Seldon Sept. 10, 1940 2,221,347 Giesler Nov. 12, 1940 2,293,947 Persons Aug. 25, 1942 2,298,163 Raney Oct. 6, 1942 2,307,723 Anderson Jan. 5, 1943 2,479,307 Cam-illi Aug. 16, 1949 2,490,919 Raney Dec. 13, 1949 2,507,911 Keller May 16, 1950 2,534,497 Albright Dec. 19, 1950 

